comparisons between cellulase production by aspergillus fumigatus in agitated vessels and in an air-lift fermentor

aspergillus fumigatus was cultured in disc-turbine-agitated vessels and in an air-lift fermentor. in the agitated vessels the yield of cellulase was reduced when the agitation rate was increased, although extracellular protein levels rose. the enzyme complex itself was shown to be exceptionally stable under conditions similar to those in ..

carbon fiber/resin matrix interphase: effect of carbon fiber surface treatment on composite performance

carbon fibers are supplied by manufacturers with a predetermined level of surface treatment and matrix compatible sizings. surface treatment of hysol grafil xa increases the active oxygen content, polarity and total free surface energy. this study is directed toward determining the effect of varying surface treatments on performance of th..

cellulose-reinforced nylon-reaction injection molded composites

the properties of cellulose-reinforced nylon-6 block copolymers were studied. composites were prepared by the reaction injection molding (rim) of a nylon system in which one of the reactants contained cellulose fibers. incorporation of cellulose fibers into the liquid reactant of the nylon-rim system resulted in increased viscosity, depen..

laser machining of aero engine components

many of the early developments in using lasers in machining revolved around high powered co//2, ruby, and nd-glass lasers. such systems have cornered a share of the sheet metal fabrication market, but are not suitable for precision drilling. for small holes, such lasers can only be used in a 'direct drilling' mode where the laser is focus..

case study of the biodeterioration of some boot uppers made from a polyurethane poromeric

reinoculation of a range of microbial isolates showed fungal attack to be the reason for the deterioration of some boots with polyester polyurethane (pu) poromeric uppers. bacteria were not implicated although they had grown along nylon fibers in the poromeric. flaking of the top coating of the pu foam layer resulted from surface growth, ..

effect of mica surface treatment on mechanical properties of mica-flake-reinforced cement composites

to determine how the surface modification of mica influences flexural strength and fracture toughness of mica-reinforced cement composites, mica was treated with hf acid and three coupling agents: two silanes (cvbs, $gamma$ mps) and a titanate (idt). significant increases in mechanical properties resulted, depending on type of treatment, ..

characterization of interface states at ni/ncdf//2 schottky barrier type diodes and the effect of cdf//2 surface preparation

two schottky diodes were fabricated by evaporation of nickel on to an n-type cdf//2:yf//3 semiconductor diode a was prepared on a slightly etched polished surface and diode b on an unpolished strongly etched surface. the current-voltage (i-v), capacitance-voltage (c-v), and conductance-voltage (g-v) characteristics were determined at room..

role of the interface in cellulose-polymer composites

cellulose fiber, a versatile and renewable natural resource, has potential use as a reinforcement for polymers. this thesis deals with the preparation of cellulose-polymer composites and their properties, paying most attention to the effects of interfacial adhesion. cellulose fibers introduced into the liquid reactant of the nylon system ..

debonding and pull-out properties of coated kevlar fibres from an expoxy resin matrix

single filament pull-out tests on uncoated kevlar/epoxy resin composites have already been studied by l. s. penn and s. m. lee this note presents the debonding and pull-out properties of the coated kevlar/epoxy resin composites using single strand pull-out experiments. the fundamental properties such as mode ii fiber debond toughness, spe..

anaerobic fermentation: microbes from ruminants

fed-batch fermentation of biomass could provide a route for direct conversion of renewable resources to commercially significant chemicals. the cellulose fermentation in the rumen is impacted by the physically and chemically heterogeneous character of the insoluble substrate, as well as the properties of the mixed culture responsible for ..